Question

I am trying to send a message to a game (to automate text commands), the problem is that I can’t figure out how to use the information from spy++ to write a C# sendmessage function.

I was able to use spy++ to get
00220540 S WM_SETCURSOR hwnd:0024052C nHittest:HTCLIENT wMouseMsg:WM_MOUSEMOVE

Could anyone provide a breakdown of what this means, and how to send the message to the game in c#?

EDIT:

I found out that I was looking at the wrong process. Instead of looking at the javaw.exe, I was looking at the actual game.

Here is the code for pressing t:

<00919> 0038062A WM_INPUT nInputCode:RIM_INPUT hRawInput:189E0973
<00920> 0024052 P WM_KEYUP nVirtKey:'T' cRepeat:1 ScanCode:14fExtended:0fAltDown:0fRepeat:1fUp:1

Answer 1

So lets start with the signature for SendMessage, from Pinvoke.net:

[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);

It taks a window handle, hWnd, a message ID, Msg, and two generic parameters wParam and lParam which change meaing based on the message ID.

What spy++ is showing you is the parameters that were sent to SendMessage. As you can see it doesn’t show you wParam and lParam, but hwnd, nHittest, and wMouseMsg. That’s because Spy++ knows what the wParam and lParam parameters actually mean for a WM_SETCURSOR message and is decoding them for you.

So decoding each piece of the what Spy++ has sent:

1. 00220540 – the window handle receiving the message – the hWnd parameter.
2. S – It means it was sent via
   SendMessage() and not posted via
   PostMessage(). See http://msdn.microsoft.com/en-us/library/aa265147(v=vs.60).aspx
3. WM_SETCURSOR – The message ID – the
   Msg parameter.
4. hwnd:0024052C – handle of the Window
   containing the cursor – the wParam
   parameter.
5. nHittest:HTCLIENT – the hit test
   code – the low word of the lParam
   parameter.
6. wMouseMsg:WM_MOUSEMOVE – the mouse
   message – the high word of the
   lParam parameter.

The way you would go about sending the message to a window is:

enum WindowMessages {
    WM_SETCURSOR  = 0x0020,
    WM_MOUSEMOVE  = 0x0200,
    ....
}

enum HitTestCodes {
    HTCLIENT = 1,
    ....
}

....
IntPtr hWnd = [get your window handle some how]
int lParam = ((int)WindowMessages.WM_MOUSEMOVE) << 16 + (int)HitTestCodes.HTCLIENT;
SendMessage(hWnd, (uint)WindowMessages.WM_SETCURSOR, hWnd, (IntPtr)lParam);

For understanding what other messages mean you can do a search on Msdn.com for the messsage in the Windows documentation.

So after answering all of that I don’t think this will have anything to do with sending keys to the game you are trying to control. WM_SETCURSOR doesn’t have anything to do with keyboard input.